perf tools: Don't clone maps from parent when synthesizing forks
[linux/fpc-iii.git] / drivers / idle / intel_idle.c
blob8b5d85c91e9d4b2ed10d07bf98237c9f6b7eff14
1 /*
2 * intel_idle.c - native hardware idle loop for modern Intel processors
4 * Copyright (c) 2013, Intel Corporation.
5 * Len Brown <len.brown@intel.com>
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
22 * intel_idle is a cpuidle driver that loads on specific Intel processors
23 * in lieu of the legacy ACPI processor_idle driver. The intent is to
24 * make Linux more efficient on these processors, as intel_idle knows
25 * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
29 * Design Assumptions
31 * All CPUs have same idle states as boot CPU
33 * Chipset BM_STS (bus master status) bit is a NOP
34 * for preventing entry into deep C-stats
38 * Known limitations
40 * The driver currently initializes for_each_online_cpu() upon modprobe.
41 * It it unaware of subsequent processors hot-added to the system.
42 * This means that if you boot with maxcpus=n and later online
43 * processors above n, those processors will use C1 only.
45 * ACPI has a .suspend hack to turn off deep c-statees during suspend
46 * to avoid complications with the lapic timer workaround.
47 * Have not seen issues with suspend, but may need same workaround here.
51 /* un-comment DEBUG to enable pr_debug() statements */
52 #define DEBUG
54 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
56 #include <linux/kernel.h>
57 #include <linux/cpuidle.h>
58 #include <linux/tick.h>
59 #include <trace/events/power.h>
60 #include <linux/sched.h>
61 #include <linux/notifier.h>
62 #include <linux/cpu.h>
63 #include <linux/moduleparam.h>
64 #include <asm/cpu_device_id.h>
65 #include <asm/intel-family.h>
66 #include <asm/mwait.h>
67 #include <asm/msr.h>
69 #define INTEL_IDLE_VERSION "0.4.1"
71 static struct cpuidle_driver intel_idle_driver = {
72 .name = "intel_idle",
73 .owner = THIS_MODULE,
75 /* intel_idle.max_cstate=0 disables driver */
76 static int max_cstate = CPUIDLE_STATE_MAX - 1;
78 static unsigned int mwait_substates;
80 #define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
81 /* Reliable LAPIC Timer States, bit 1 for C1 etc. */
82 static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
84 struct idle_cpu {
85 struct cpuidle_state *state_table;
88 * Hardware C-state auto-demotion may not always be optimal.
89 * Indicate which enable bits to clear here.
91 unsigned long auto_demotion_disable_flags;
92 bool byt_auto_demotion_disable_flag;
93 bool disable_promotion_to_c1e;
96 static const struct idle_cpu *icpu;
97 static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
98 static int intel_idle(struct cpuidle_device *dev,
99 struct cpuidle_driver *drv, int index);
100 static void intel_idle_s2idle(struct cpuidle_device *dev,
101 struct cpuidle_driver *drv, int index);
102 static struct cpuidle_state *cpuidle_state_table;
105 * Set this flag for states where the HW flushes the TLB for us
106 * and so we don't need cross-calls to keep it consistent.
107 * If this flag is set, SW flushes the TLB, so even if the
108 * HW doesn't do the flushing, this flag is safe to use.
110 #define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
113 * MWAIT takes an 8-bit "hint" in EAX "suggesting"
114 * the C-state (top nibble) and sub-state (bottom nibble)
115 * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
117 * We store the hint at the top of our "flags" for each state.
119 #define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
120 #define MWAIT2flg(eax) ((eax & 0xFF) << 24)
123 * States are indexed by the cstate number,
124 * which is also the index into the MWAIT hint array.
125 * Thus C0 is a dummy.
127 static struct cpuidle_state nehalem_cstates[] = {
129 .name = "C1",
130 .desc = "MWAIT 0x00",
131 .flags = MWAIT2flg(0x00),
132 .exit_latency = 3,
133 .target_residency = 6,
134 .enter = &intel_idle,
135 .enter_s2idle = intel_idle_s2idle, },
137 .name = "C1E",
138 .desc = "MWAIT 0x01",
139 .flags = MWAIT2flg(0x01),
140 .exit_latency = 10,
141 .target_residency = 20,
142 .enter = &intel_idle,
143 .enter_s2idle = intel_idle_s2idle, },
145 .name = "C3",
146 .desc = "MWAIT 0x10",
147 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
148 .exit_latency = 20,
149 .target_residency = 80,
150 .enter = &intel_idle,
151 .enter_s2idle = intel_idle_s2idle, },
153 .name = "C6",
154 .desc = "MWAIT 0x20",
155 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
156 .exit_latency = 200,
157 .target_residency = 800,
158 .enter = &intel_idle,
159 .enter_s2idle = intel_idle_s2idle, },
161 .enter = NULL }
164 static struct cpuidle_state snb_cstates[] = {
166 .name = "C1",
167 .desc = "MWAIT 0x00",
168 .flags = MWAIT2flg(0x00),
169 .exit_latency = 2,
170 .target_residency = 2,
171 .enter = &intel_idle,
172 .enter_s2idle = intel_idle_s2idle, },
174 .name = "C1E",
175 .desc = "MWAIT 0x01",
176 .flags = MWAIT2flg(0x01),
177 .exit_latency = 10,
178 .target_residency = 20,
179 .enter = &intel_idle,
180 .enter_s2idle = intel_idle_s2idle, },
182 .name = "C3",
183 .desc = "MWAIT 0x10",
184 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
185 .exit_latency = 80,
186 .target_residency = 211,
187 .enter = &intel_idle,
188 .enter_s2idle = intel_idle_s2idle, },
190 .name = "C6",
191 .desc = "MWAIT 0x20",
192 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
193 .exit_latency = 104,
194 .target_residency = 345,
195 .enter = &intel_idle,
196 .enter_s2idle = intel_idle_s2idle, },
198 .name = "C7",
199 .desc = "MWAIT 0x30",
200 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
201 .exit_latency = 109,
202 .target_residency = 345,
203 .enter = &intel_idle,
204 .enter_s2idle = intel_idle_s2idle, },
206 .enter = NULL }
209 static struct cpuidle_state byt_cstates[] = {
211 .name = "C1",
212 .desc = "MWAIT 0x00",
213 .flags = MWAIT2flg(0x00),
214 .exit_latency = 1,
215 .target_residency = 1,
216 .enter = &intel_idle,
217 .enter_s2idle = intel_idle_s2idle, },
219 .name = "C6N",
220 .desc = "MWAIT 0x58",
221 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
222 .exit_latency = 300,
223 .target_residency = 275,
224 .enter = &intel_idle,
225 .enter_s2idle = intel_idle_s2idle, },
227 .name = "C6S",
228 .desc = "MWAIT 0x52",
229 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
230 .exit_latency = 500,
231 .target_residency = 560,
232 .enter = &intel_idle,
233 .enter_s2idle = intel_idle_s2idle, },
235 .name = "C7",
236 .desc = "MWAIT 0x60",
237 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
238 .exit_latency = 1200,
239 .target_residency = 4000,
240 .enter = &intel_idle,
241 .enter_s2idle = intel_idle_s2idle, },
243 .name = "C7S",
244 .desc = "MWAIT 0x64",
245 .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
246 .exit_latency = 10000,
247 .target_residency = 20000,
248 .enter = &intel_idle,
249 .enter_s2idle = intel_idle_s2idle, },
251 .enter = NULL }
254 static struct cpuidle_state cht_cstates[] = {
256 .name = "C1",
257 .desc = "MWAIT 0x00",
258 .flags = MWAIT2flg(0x00),
259 .exit_latency = 1,
260 .target_residency = 1,
261 .enter = &intel_idle,
262 .enter_s2idle = intel_idle_s2idle, },
264 .name = "C6N",
265 .desc = "MWAIT 0x58",
266 .flags = MWAIT2flg(0x58) | CPUIDLE_FLAG_TLB_FLUSHED,
267 .exit_latency = 80,
268 .target_residency = 275,
269 .enter = &intel_idle,
270 .enter_s2idle = intel_idle_s2idle, },
272 .name = "C6S",
273 .desc = "MWAIT 0x52",
274 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
275 .exit_latency = 200,
276 .target_residency = 560,
277 .enter = &intel_idle,
278 .enter_s2idle = intel_idle_s2idle, },
280 .name = "C7",
281 .desc = "MWAIT 0x60",
282 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
283 .exit_latency = 1200,
284 .target_residency = 4000,
285 .enter = &intel_idle,
286 .enter_s2idle = intel_idle_s2idle, },
288 .name = "C7S",
289 .desc = "MWAIT 0x64",
290 .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
291 .exit_latency = 10000,
292 .target_residency = 20000,
293 .enter = &intel_idle,
294 .enter_s2idle = intel_idle_s2idle, },
296 .enter = NULL }
299 static struct cpuidle_state ivb_cstates[] = {
301 .name = "C1",
302 .desc = "MWAIT 0x00",
303 .flags = MWAIT2flg(0x00),
304 .exit_latency = 1,
305 .target_residency = 1,
306 .enter = &intel_idle,
307 .enter_s2idle = intel_idle_s2idle, },
309 .name = "C1E",
310 .desc = "MWAIT 0x01",
311 .flags = MWAIT2flg(0x01),
312 .exit_latency = 10,
313 .target_residency = 20,
314 .enter = &intel_idle,
315 .enter_s2idle = intel_idle_s2idle, },
317 .name = "C3",
318 .desc = "MWAIT 0x10",
319 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
320 .exit_latency = 59,
321 .target_residency = 156,
322 .enter = &intel_idle,
323 .enter_s2idle = intel_idle_s2idle, },
325 .name = "C6",
326 .desc = "MWAIT 0x20",
327 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
328 .exit_latency = 80,
329 .target_residency = 300,
330 .enter = &intel_idle,
331 .enter_s2idle = intel_idle_s2idle, },
333 .name = "C7",
334 .desc = "MWAIT 0x30",
335 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
336 .exit_latency = 87,
337 .target_residency = 300,
338 .enter = &intel_idle,
339 .enter_s2idle = intel_idle_s2idle, },
341 .enter = NULL }
344 static struct cpuidle_state ivt_cstates[] = {
346 .name = "C1",
347 .desc = "MWAIT 0x00",
348 .flags = MWAIT2flg(0x00),
349 .exit_latency = 1,
350 .target_residency = 1,
351 .enter = &intel_idle,
352 .enter_s2idle = intel_idle_s2idle, },
354 .name = "C1E",
355 .desc = "MWAIT 0x01",
356 .flags = MWAIT2flg(0x01),
357 .exit_latency = 10,
358 .target_residency = 80,
359 .enter = &intel_idle,
360 .enter_s2idle = intel_idle_s2idle, },
362 .name = "C3",
363 .desc = "MWAIT 0x10",
364 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
365 .exit_latency = 59,
366 .target_residency = 156,
367 .enter = &intel_idle,
368 .enter_s2idle = intel_idle_s2idle, },
370 .name = "C6",
371 .desc = "MWAIT 0x20",
372 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
373 .exit_latency = 82,
374 .target_residency = 300,
375 .enter = &intel_idle,
376 .enter_s2idle = intel_idle_s2idle, },
378 .enter = NULL }
381 static struct cpuidle_state ivt_cstates_4s[] = {
383 .name = "C1",
384 .desc = "MWAIT 0x00",
385 .flags = MWAIT2flg(0x00),
386 .exit_latency = 1,
387 .target_residency = 1,
388 .enter = &intel_idle,
389 .enter_s2idle = intel_idle_s2idle, },
391 .name = "C1E",
392 .desc = "MWAIT 0x01",
393 .flags = MWAIT2flg(0x01),
394 .exit_latency = 10,
395 .target_residency = 250,
396 .enter = &intel_idle,
397 .enter_s2idle = intel_idle_s2idle, },
399 .name = "C3",
400 .desc = "MWAIT 0x10",
401 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
402 .exit_latency = 59,
403 .target_residency = 300,
404 .enter = &intel_idle,
405 .enter_s2idle = intel_idle_s2idle, },
407 .name = "C6",
408 .desc = "MWAIT 0x20",
409 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
410 .exit_latency = 84,
411 .target_residency = 400,
412 .enter = &intel_idle,
413 .enter_s2idle = intel_idle_s2idle, },
415 .enter = NULL }
418 static struct cpuidle_state ivt_cstates_8s[] = {
420 .name = "C1",
421 .desc = "MWAIT 0x00",
422 .flags = MWAIT2flg(0x00),
423 .exit_latency = 1,
424 .target_residency = 1,
425 .enter = &intel_idle,
426 .enter_s2idle = intel_idle_s2idle, },
428 .name = "C1E",
429 .desc = "MWAIT 0x01",
430 .flags = MWAIT2flg(0x01),
431 .exit_latency = 10,
432 .target_residency = 500,
433 .enter = &intel_idle,
434 .enter_s2idle = intel_idle_s2idle, },
436 .name = "C3",
437 .desc = "MWAIT 0x10",
438 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
439 .exit_latency = 59,
440 .target_residency = 600,
441 .enter = &intel_idle,
442 .enter_s2idle = intel_idle_s2idle, },
444 .name = "C6",
445 .desc = "MWAIT 0x20",
446 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
447 .exit_latency = 88,
448 .target_residency = 700,
449 .enter = &intel_idle,
450 .enter_s2idle = intel_idle_s2idle, },
452 .enter = NULL }
455 static struct cpuidle_state hsw_cstates[] = {
457 .name = "C1",
458 .desc = "MWAIT 0x00",
459 .flags = MWAIT2flg(0x00),
460 .exit_latency = 2,
461 .target_residency = 2,
462 .enter = &intel_idle,
463 .enter_s2idle = intel_idle_s2idle, },
465 .name = "C1E",
466 .desc = "MWAIT 0x01",
467 .flags = MWAIT2flg(0x01),
468 .exit_latency = 10,
469 .target_residency = 20,
470 .enter = &intel_idle,
471 .enter_s2idle = intel_idle_s2idle, },
473 .name = "C3",
474 .desc = "MWAIT 0x10",
475 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
476 .exit_latency = 33,
477 .target_residency = 100,
478 .enter = &intel_idle,
479 .enter_s2idle = intel_idle_s2idle, },
481 .name = "C6",
482 .desc = "MWAIT 0x20",
483 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
484 .exit_latency = 133,
485 .target_residency = 400,
486 .enter = &intel_idle,
487 .enter_s2idle = intel_idle_s2idle, },
489 .name = "C7s",
490 .desc = "MWAIT 0x32",
491 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
492 .exit_latency = 166,
493 .target_residency = 500,
494 .enter = &intel_idle,
495 .enter_s2idle = intel_idle_s2idle, },
497 .name = "C8",
498 .desc = "MWAIT 0x40",
499 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
500 .exit_latency = 300,
501 .target_residency = 900,
502 .enter = &intel_idle,
503 .enter_s2idle = intel_idle_s2idle, },
505 .name = "C9",
506 .desc = "MWAIT 0x50",
507 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
508 .exit_latency = 600,
509 .target_residency = 1800,
510 .enter = &intel_idle,
511 .enter_s2idle = intel_idle_s2idle, },
513 .name = "C10",
514 .desc = "MWAIT 0x60",
515 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
516 .exit_latency = 2600,
517 .target_residency = 7700,
518 .enter = &intel_idle,
519 .enter_s2idle = intel_idle_s2idle, },
521 .enter = NULL }
523 static struct cpuidle_state bdw_cstates[] = {
525 .name = "C1",
526 .desc = "MWAIT 0x00",
527 .flags = MWAIT2flg(0x00),
528 .exit_latency = 2,
529 .target_residency = 2,
530 .enter = &intel_idle,
531 .enter_s2idle = intel_idle_s2idle, },
533 .name = "C1E",
534 .desc = "MWAIT 0x01",
535 .flags = MWAIT2flg(0x01),
536 .exit_latency = 10,
537 .target_residency = 20,
538 .enter = &intel_idle,
539 .enter_s2idle = intel_idle_s2idle, },
541 .name = "C3",
542 .desc = "MWAIT 0x10",
543 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
544 .exit_latency = 40,
545 .target_residency = 100,
546 .enter = &intel_idle,
547 .enter_s2idle = intel_idle_s2idle, },
549 .name = "C6",
550 .desc = "MWAIT 0x20",
551 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
552 .exit_latency = 133,
553 .target_residency = 400,
554 .enter = &intel_idle,
555 .enter_s2idle = intel_idle_s2idle, },
557 .name = "C7s",
558 .desc = "MWAIT 0x32",
559 .flags = MWAIT2flg(0x32) | CPUIDLE_FLAG_TLB_FLUSHED,
560 .exit_latency = 166,
561 .target_residency = 500,
562 .enter = &intel_idle,
563 .enter_s2idle = intel_idle_s2idle, },
565 .name = "C8",
566 .desc = "MWAIT 0x40",
567 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
568 .exit_latency = 300,
569 .target_residency = 900,
570 .enter = &intel_idle,
571 .enter_s2idle = intel_idle_s2idle, },
573 .name = "C9",
574 .desc = "MWAIT 0x50",
575 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
576 .exit_latency = 600,
577 .target_residency = 1800,
578 .enter = &intel_idle,
579 .enter_s2idle = intel_idle_s2idle, },
581 .name = "C10",
582 .desc = "MWAIT 0x60",
583 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
584 .exit_latency = 2600,
585 .target_residency = 7700,
586 .enter = &intel_idle,
587 .enter_s2idle = intel_idle_s2idle, },
589 .enter = NULL }
592 static struct cpuidle_state skl_cstates[] = {
594 .name = "C1",
595 .desc = "MWAIT 0x00",
596 .flags = MWAIT2flg(0x00),
597 .exit_latency = 2,
598 .target_residency = 2,
599 .enter = &intel_idle,
600 .enter_s2idle = intel_idle_s2idle, },
602 .name = "C1E",
603 .desc = "MWAIT 0x01",
604 .flags = MWAIT2flg(0x01),
605 .exit_latency = 10,
606 .target_residency = 20,
607 .enter = &intel_idle,
608 .enter_s2idle = intel_idle_s2idle, },
610 .name = "C3",
611 .desc = "MWAIT 0x10",
612 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
613 .exit_latency = 70,
614 .target_residency = 100,
615 .enter = &intel_idle,
616 .enter_s2idle = intel_idle_s2idle, },
618 .name = "C6",
619 .desc = "MWAIT 0x20",
620 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
621 .exit_latency = 85,
622 .target_residency = 200,
623 .enter = &intel_idle,
624 .enter_s2idle = intel_idle_s2idle, },
626 .name = "C7s",
627 .desc = "MWAIT 0x33",
628 .flags = MWAIT2flg(0x33) | CPUIDLE_FLAG_TLB_FLUSHED,
629 .exit_latency = 124,
630 .target_residency = 800,
631 .enter = &intel_idle,
632 .enter_s2idle = intel_idle_s2idle, },
634 .name = "C8",
635 .desc = "MWAIT 0x40",
636 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
637 .exit_latency = 200,
638 .target_residency = 800,
639 .enter = &intel_idle,
640 .enter_s2idle = intel_idle_s2idle, },
642 .name = "C9",
643 .desc = "MWAIT 0x50",
644 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
645 .exit_latency = 480,
646 .target_residency = 5000,
647 .enter = &intel_idle,
648 .enter_s2idle = intel_idle_s2idle, },
650 .name = "C10",
651 .desc = "MWAIT 0x60",
652 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
653 .exit_latency = 890,
654 .target_residency = 5000,
655 .enter = &intel_idle,
656 .enter_s2idle = intel_idle_s2idle, },
658 .enter = NULL }
661 static struct cpuidle_state skx_cstates[] = {
663 .name = "C1",
664 .desc = "MWAIT 0x00",
665 .flags = MWAIT2flg(0x00),
666 .exit_latency = 2,
667 .target_residency = 2,
668 .enter = &intel_idle,
669 .enter_s2idle = intel_idle_s2idle, },
671 .name = "C1E",
672 .desc = "MWAIT 0x01",
673 .flags = MWAIT2flg(0x01),
674 .exit_latency = 10,
675 .target_residency = 20,
676 .enter = &intel_idle,
677 .enter_s2idle = intel_idle_s2idle, },
679 .name = "C6",
680 .desc = "MWAIT 0x20",
681 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
682 .exit_latency = 133,
683 .target_residency = 600,
684 .enter = &intel_idle,
685 .enter_s2idle = intel_idle_s2idle, },
687 .enter = NULL }
690 static struct cpuidle_state atom_cstates[] = {
692 .name = "C1E",
693 .desc = "MWAIT 0x00",
694 .flags = MWAIT2flg(0x00),
695 .exit_latency = 10,
696 .target_residency = 20,
697 .enter = &intel_idle,
698 .enter_s2idle = intel_idle_s2idle, },
700 .name = "C2",
701 .desc = "MWAIT 0x10",
702 .flags = MWAIT2flg(0x10),
703 .exit_latency = 20,
704 .target_residency = 80,
705 .enter = &intel_idle,
706 .enter_s2idle = intel_idle_s2idle, },
708 .name = "C4",
709 .desc = "MWAIT 0x30",
710 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
711 .exit_latency = 100,
712 .target_residency = 400,
713 .enter = &intel_idle,
714 .enter_s2idle = intel_idle_s2idle, },
716 .name = "C6",
717 .desc = "MWAIT 0x52",
718 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
719 .exit_latency = 140,
720 .target_residency = 560,
721 .enter = &intel_idle,
722 .enter_s2idle = intel_idle_s2idle, },
724 .enter = NULL }
726 static struct cpuidle_state tangier_cstates[] = {
728 .name = "C1",
729 .desc = "MWAIT 0x00",
730 .flags = MWAIT2flg(0x00),
731 .exit_latency = 1,
732 .target_residency = 4,
733 .enter = &intel_idle,
734 .enter_s2idle = intel_idle_s2idle, },
736 .name = "C4",
737 .desc = "MWAIT 0x30",
738 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TLB_FLUSHED,
739 .exit_latency = 100,
740 .target_residency = 400,
741 .enter = &intel_idle,
742 .enter_s2idle = intel_idle_s2idle, },
744 .name = "C6",
745 .desc = "MWAIT 0x52",
746 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TLB_FLUSHED,
747 .exit_latency = 140,
748 .target_residency = 560,
749 .enter = &intel_idle,
750 .enter_s2idle = intel_idle_s2idle, },
752 .name = "C7",
753 .desc = "MWAIT 0x60",
754 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
755 .exit_latency = 1200,
756 .target_residency = 4000,
757 .enter = &intel_idle,
758 .enter_s2idle = intel_idle_s2idle, },
760 .name = "C9",
761 .desc = "MWAIT 0x64",
762 .flags = MWAIT2flg(0x64) | CPUIDLE_FLAG_TLB_FLUSHED,
763 .exit_latency = 10000,
764 .target_residency = 20000,
765 .enter = &intel_idle,
766 .enter_s2idle = intel_idle_s2idle, },
768 .enter = NULL }
770 static struct cpuidle_state avn_cstates[] = {
772 .name = "C1",
773 .desc = "MWAIT 0x00",
774 .flags = MWAIT2flg(0x00),
775 .exit_latency = 2,
776 .target_residency = 2,
777 .enter = &intel_idle,
778 .enter_s2idle = intel_idle_s2idle, },
780 .name = "C6",
781 .desc = "MWAIT 0x51",
782 .flags = MWAIT2flg(0x51) | CPUIDLE_FLAG_TLB_FLUSHED,
783 .exit_latency = 15,
784 .target_residency = 45,
785 .enter = &intel_idle,
786 .enter_s2idle = intel_idle_s2idle, },
788 .enter = NULL }
790 static struct cpuidle_state knl_cstates[] = {
792 .name = "C1",
793 .desc = "MWAIT 0x00",
794 .flags = MWAIT2flg(0x00),
795 .exit_latency = 1,
796 .target_residency = 2,
797 .enter = &intel_idle,
798 .enter_s2idle = intel_idle_s2idle },
800 .name = "C6",
801 .desc = "MWAIT 0x10",
802 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TLB_FLUSHED,
803 .exit_latency = 120,
804 .target_residency = 500,
805 .enter = &intel_idle,
806 .enter_s2idle = intel_idle_s2idle },
808 .enter = NULL }
811 static struct cpuidle_state bxt_cstates[] = {
813 .name = "C1",
814 .desc = "MWAIT 0x00",
815 .flags = MWAIT2flg(0x00),
816 .exit_latency = 2,
817 .target_residency = 2,
818 .enter = &intel_idle,
819 .enter_s2idle = intel_idle_s2idle, },
821 .name = "C1E",
822 .desc = "MWAIT 0x01",
823 .flags = MWAIT2flg(0x01),
824 .exit_latency = 10,
825 .target_residency = 20,
826 .enter = &intel_idle,
827 .enter_s2idle = intel_idle_s2idle, },
829 .name = "C6",
830 .desc = "MWAIT 0x20",
831 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
832 .exit_latency = 133,
833 .target_residency = 133,
834 .enter = &intel_idle,
835 .enter_s2idle = intel_idle_s2idle, },
837 .name = "C7s",
838 .desc = "MWAIT 0x31",
839 .flags = MWAIT2flg(0x31) | CPUIDLE_FLAG_TLB_FLUSHED,
840 .exit_latency = 155,
841 .target_residency = 155,
842 .enter = &intel_idle,
843 .enter_s2idle = intel_idle_s2idle, },
845 .name = "C8",
846 .desc = "MWAIT 0x40",
847 .flags = MWAIT2flg(0x40) | CPUIDLE_FLAG_TLB_FLUSHED,
848 .exit_latency = 1000,
849 .target_residency = 1000,
850 .enter = &intel_idle,
851 .enter_s2idle = intel_idle_s2idle, },
853 .name = "C9",
854 .desc = "MWAIT 0x50",
855 .flags = MWAIT2flg(0x50) | CPUIDLE_FLAG_TLB_FLUSHED,
856 .exit_latency = 2000,
857 .target_residency = 2000,
858 .enter = &intel_idle,
859 .enter_s2idle = intel_idle_s2idle, },
861 .name = "C10",
862 .desc = "MWAIT 0x60",
863 .flags = MWAIT2flg(0x60) | CPUIDLE_FLAG_TLB_FLUSHED,
864 .exit_latency = 10000,
865 .target_residency = 10000,
866 .enter = &intel_idle,
867 .enter_s2idle = intel_idle_s2idle, },
869 .enter = NULL }
872 static struct cpuidle_state dnv_cstates[] = {
874 .name = "C1",
875 .desc = "MWAIT 0x00",
876 .flags = MWAIT2flg(0x00),
877 .exit_latency = 2,
878 .target_residency = 2,
879 .enter = &intel_idle,
880 .enter_s2idle = intel_idle_s2idle, },
882 .name = "C1E",
883 .desc = "MWAIT 0x01",
884 .flags = MWAIT2flg(0x01),
885 .exit_latency = 10,
886 .target_residency = 20,
887 .enter = &intel_idle,
888 .enter_s2idle = intel_idle_s2idle, },
890 .name = "C6",
891 .desc = "MWAIT 0x20",
892 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TLB_FLUSHED,
893 .exit_latency = 50,
894 .target_residency = 500,
895 .enter = &intel_idle,
896 .enter_s2idle = intel_idle_s2idle, },
898 .enter = NULL }
902 * intel_idle
903 * @dev: cpuidle_device
904 * @drv: cpuidle driver
905 * @index: index of cpuidle state
907 * Must be called under local_irq_disable().
909 static __cpuidle int intel_idle(struct cpuidle_device *dev,
910 struct cpuidle_driver *drv, int index)
912 unsigned long ecx = 1; /* break on interrupt flag */
913 struct cpuidle_state *state = &drv->states[index];
914 unsigned long eax = flg2MWAIT(state->flags);
915 unsigned int cstate;
916 bool uninitialized_var(tick);
917 int cpu = smp_processor_id();
920 * leave_mm() to avoid costly and often unnecessary wakeups
921 * for flushing the user TLB's associated with the active mm.
923 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
924 leave_mm(cpu);
926 if (!static_cpu_has(X86_FEATURE_ARAT)) {
927 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) &
928 MWAIT_CSTATE_MASK) + 1;
929 tick = false;
930 if (!(lapic_timer_reliable_states & (1 << (cstate)))) {
931 tick = true;
932 tick_broadcast_enter();
936 mwait_idle_with_hints(eax, ecx);
938 if (!static_cpu_has(X86_FEATURE_ARAT) && tick)
939 tick_broadcast_exit();
941 return index;
945 * intel_idle_s2idle - simplified "enter" callback routine for suspend-to-idle
946 * @dev: cpuidle_device
947 * @drv: cpuidle driver
948 * @index: state index
950 static void intel_idle_s2idle(struct cpuidle_device *dev,
951 struct cpuidle_driver *drv, int index)
953 unsigned long ecx = 1; /* break on interrupt flag */
954 unsigned long eax = flg2MWAIT(drv->states[index].flags);
956 mwait_idle_with_hints(eax, ecx);
959 static void __setup_broadcast_timer(bool on)
961 if (on)
962 tick_broadcast_enable();
963 else
964 tick_broadcast_disable();
967 static void auto_demotion_disable(void)
969 unsigned long long msr_bits;
971 rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
972 msr_bits &= ~(icpu->auto_demotion_disable_flags);
973 wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr_bits);
975 static void c1e_promotion_disable(void)
977 unsigned long long msr_bits;
979 rdmsrl(MSR_IA32_POWER_CTL, msr_bits);
980 msr_bits &= ~0x2;
981 wrmsrl(MSR_IA32_POWER_CTL, msr_bits);
984 static const struct idle_cpu idle_cpu_nehalem = {
985 .state_table = nehalem_cstates,
986 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
987 .disable_promotion_to_c1e = true,
990 static const struct idle_cpu idle_cpu_atom = {
991 .state_table = atom_cstates,
994 static const struct idle_cpu idle_cpu_tangier = {
995 .state_table = tangier_cstates,
998 static const struct idle_cpu idle_cpu_lincroft = {
999 .state_table = atom_cstates,
1000 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
1003 static const struct idle_cpu idle_cpu_snb = {
1004 .state_table = snb_cstates,
1005 .disable_promotion_to_c1e = true,
1008 static const struct idle_cpu idle_cpu_byt = {
1009 .state_table = byt_cstates,
1010 .disable_promotion_to_c1e = true,
1011 .byt_auto_demotion_disable_flag = true,
1014 static const struct idle_cpu idle_cpu_cht = {
1015 .state_table = cht_cstates,
1016 .disable_promotion_to_c1e = true,
1017 .byt_auto_demotion_disable_flag = true,
1020 static const struct idle_cpu idle_cpu_ivb = {
1021 .state_table = ivb_cstates,
1022 .disable_promotion_to_c1e = true,
1025 static const struct idle_cpu idle_cpu_ivt = {
1026 .state_table = ivt_cstates,
1027 .disable_promotion_to_c1e = true,
1030 static const struct idle_cpu idle_cpu_hsw = {
1031 .state_table = hsw_cstates,
1032 .disable_promotion_to_c1e = true,
1035 static const struct idle_cpu idle_cpu_bdw = {
1036 .state_table = bdw_cstates,
1037 .disable_promotion_to_c1e = true,
1040 static const struct idle_cpu idle_cpu_skl = {
1041 .state_table = skl_cstates,
1042 .disable_promotion_to_c1e = true,
1045 static const struct idle_cpu idle_cpu_skx = {
1046 .state_table = skx_cstates,
1047 .disable_promotion_to_c1e = true,
1050 static const struct idle_cpu idle_cpu_avn = {
1051 .state_table = avn_cstates,
1052 .disable_promotion_to_c1e = true,
1055 static const struct idle_cpu idle_cpu_knl = {
1056 .state_table = knl_cstates,
1059 static const struct idle_cpu idle_cpu_bxt = {
1060 .state_table = bxt_cstates,
1061 .disable_promotion_to_c1e = true,
1064 static const struct idle_cpu idle_cpu_dnv = {
1065 .state_table = dnv_cstates,
1066 .disable_promotion_to_c1e = true,
1069 static const struct x86_cpu_id intel_idle_ids[] __initconst = {
1070 INTEL_CPU_FAM6(NEHALEM_EP, idle_cpu_nehalem),
1071 INTEL_CPU_FAM6(NEHALEM, idle_cpu_nehalem),
1072 INTEL_CPU_FAM6(NEHALEM_G, idle_cpu_nehalem),
1073 INTEL_CPU_FAM6(WESTMERE, idle_cpu_nehalem),
1074 INTEL_CPU_FAM6(WESTMERE_EP, idle_cpu_nehalem),
1075 INTEL_CPU_FAM6(NEHALEM_EX, idle_cpu_nehalem),
1076 INTEL_CPU_FAM6(ATOM_BONNELL, idle_cpu_atom),
1077 INTEL_CPU_FAM6(ATOM_BONNELL_MID, idle_cpu_lincroft),
1078 INTEL_CPU_FAM6(WESTMERE_EX, idle_cpu_nehalem),
1079 INTEL_CPU_FAM6(SANDYBRIDGE, idle_cpu_snb),
1080 INTEL_CPU_FAM6(SANDYBRIDGE_X, idle_cpu_snb),
1081 INTEL_CPU_FAM6(ATOM_SALTWELL, idle_cpu_atom),
1082 INTEL_CPU_FAM6(ATOM_SILVERMONT, idle_cpu_byt),
1083 INTEL_CPU_FAM6(ATOM_SILVERMONT_MID, idle_cpu_tangier),
1084 INTEL_CPU_FAM6(ATOM_AIRMONT, idle_cpu_cht),
1085 INTEL_CPU_FAM6(IVYBRIDGE, idle_cpu_ivb),
1086 INTEL_CPU_FAM6(IVYBRIDGE_X, idle_cpu_ivt),
1087 INTEL_CPU_FAM6(HASWELL_CORE, idle_cpu_hsw),
1088 INTEL_CPU_FAM6(HASWELL_X, idle_cpu_hsw),
1089 INTEL_CPU_FAM6(HASWELL_ULT, idle_cpu_hsw),
1090 INTEL_CPU_FAM6(HASWELL_GT3E, idle_cpu_hsw),
1091 INTEL_CPU_FAM6(ATOM_SILVERMONT_X, idle_cpu_avn),
1092 INTEL_CPU_FAM6(BROADWELL_CORE, idle_cpu_bdw),
1093 INTEL_CPU_FAM6(BROADWELL_GT3E, idle_cpu_bdw),
1094 INTEL_CPU_FAM6(BROADWELL_X, idle_cpu_bdw),
1095 INTEL_CPU_FAM6(BROADWELL_XEON_D, idle_cpu_bdw),
1096 INTEL_CPU_FAM6(SKYLAKE_MOBILE, idle_cpu_skl),
1097 INTEL_CPU_FAM6(SKYLAKE_DESKTOP, idle_cpu_skl),
1098 INTEL_CPU_FAM6(KABYLAKE_MOBILE, idle_cpu_skl),
1099 INTEL_CPU_FAM6(KABYLAKE_DESKTOP, idle_cpu_skl),
1100 INTEL_CPU_FAM6(SKYLAKE_X, idle_cpu_skx),
1101 INTEL_CPU_FAM6(XEON_PHI_KNL, idle_cpu_knl),
1102 INTEL_CPU_FAM6(XEON_PHI_KNM, idle_cpu_knl),
1103 INTEL_CPU_FAM6(ATOM_GOLDMONT, idle_cpu_bxt),
1104 INTEL_CPU_FAM6(ATOM_GOLDMONT_PLUS, idle_cpu_bxt),
1105 INTEL_CPU_FAM6(ATOM_GOLDMONT_X, idle_cpu_dnv),
1110 * intel_idle_probe()
1112 static int __init intel_idle_probe(void)
1114 unsigned int eax, ebx, ecx;
1115 const struct x86_cpu_id *id;
1117 if (max_cstate == 0) {
1118 pr_debug("disabled\n");
1119 return -EPERM;
1122 id = x86_match_cpu(intel_idle_ids);
1123 if (!id) {
1124 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
1125 boot_cpu_data.x86 == 6)
1126 pr_debug("does not run on family %d model %d\n",
1127 boot_cpu_data.x86, boot_cpu_data.x86_model);
1128 return -ENODEV;
1131 if (!boot_cpu_has(X86_FEATURE_MWAIT)) {
1132 pr_debug("Please enable MWAIT in BIOS SETUP\n");
1133 return -ENODEV;
1136 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
1137 return -ENODEV;
1139 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
1141 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
1142 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
1143 !mwait_substates)
1144 return -ENODEV;
1146 pr_debug("MWAIT substates: 0x%x\n", mwait_substates);
1148 icpu = (const struct idle_cpu *)id->driver_data;
1149 cpuidle_state_table = icpu->state_table;
1151 pr_debug("v" INTEL_IDLE_VERSION " model 0x%X\n",
1152 boot_cpu_data.x86_model);
1154 return 0;
1158 * intel_idle_cpuidle_devices_uninit()
1159 * Unregisters the cpuidle devices.
1161 static void intel_idle_cpuidle_devices_uninit(void)
1163 int i;
1164 struct cpuidle_device *dev;
1166 for_each_online_cpu(i) {
1167 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
1168 cpuidle_unregister_device(dev);
1173 * ivt_idle_state_table_update(void)
1175 * Tune IVT multi-socket targets
1176 * Assumption: num_sockets == (max_package_num + 1)
1178 static void ivt_idle_state_table_update(void)
1180 /* IVT uses a different table for 1-2, 3-4, and > 4 sockets */
1181 int cpu, package_num, num_sockets = 1;
1183 for_each_online_cpu(cpu) {
1184 package_num = topology_physical_package_id(cpu);
1185 if (package_num + 1 > num_sockets) {
1186 num_sockets = package_num + 1;
1188 if (num_sockets > 4) {
1189 cpuidle_state_table = ivt_cstates_8s;
1190 return;
1195 if (num_sockets > 2)
1196 cpuidle_state_table = ivt_cstates_4s;
1198 /* else, 1 and 2 socket systems use default ivt_cstates */
1202 * Translate IRTL (Interrupt Response Time Limit) MSR to usec
1205 static unsigned int irtl_ns_units[] = {
1206 1, 32, 1024, 32768, 1048576, 33554432, 0, 0 };
1208 static unsigned long long irtl_2_usec(unsigned long long irtl)
1210 unsigned long long ns;
1212 if (!irtl)
1213 return 0;
1215 ns = irtl_ns_units[(irtl >> 10) & 0x7];
1217 return div64_u64((irtl & 0x3FF) * ns, 1000);
1220 * bxt_idle_state_table_update(void)
1222 * On BXT, we trust the IRTL to show the definitive maximum latency
1223 * We use the same value for target_residency.
1225 static void bxt_idle_state_table_update(void)
1227 unsigned long long msr;
1228 unsigned int usec;
1230 rdmsrl(MSR_PKGC6_IRTL, msr);
1231 usec = irtl_2_usec(msr);
1232 if (usec) {
1233 bxt_cstates[2].exit_latency = usec;
1234 bxt_cstates[2].target_residency = usec;
1237 rdmsrl(MSR_PKGC7_IRTL, msr);
1238 usec = irtl_2_usec(msr);
1239 if (usec) {
1240 bxt_cstates[3].exit_latency = usec;
1241 bxt_cstates[3].target_residency = usec;
1244 rdmsrl(MSR_PKGC8_IRTL, msr);
1245 usec = irtl_2_usec(msr);
1246 if (usec) {
1247 bxt_cstates[4].exit_latency = usec;
1248 bxt_cstates[4].target_residency = usec;
1251 rdmsrl(MSR_PKGC9_IRTL, msr);
1252 usec = irtl_2_usec(msr);
1253 if (usec) {
1254 bxt_cstates[5].exit_latency = usec;
1255 bxt_cstates[5].target_residency = usec;
1258 rdmsrl(MSR_PKGC10_IRTL, msr);
1259 usec = irtl_2_usec(msr);
1260 if (usec) {
1261 bxt_cstates[6].exit_latency = usec;
1262 bxt_cstates[6].target_residency = usec;
1267 * sklh_idle_state_table_update(void)
1269 * On SKL-H (model 0x5e) disable C8 and C9 if:
1270 * C10 is enabled and SGX disabled
1272 static void sklh_idle_state_table_update(void)
1274 unsigned long long msr;
1275 unsigned int eax, ebx, ecx, edx;
1278 /* if PC10 disabled via cmdline intel_idle.max_cstate=7 or shallower */
1279 if (max_cstate <= 7)
1280 return;
1282 /* if PC10 not present in CPUID.MWAIT.EDX */
1283 if ((mwait_substates & (0xF << 28)) == 0)
1284 return;
1286 rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, msr);
1288 /* PC10 is not enabled in PKG C-state limit */
1289 if ((msr & 0xF) != 8)
1290 return;
1292 ecx = 0;
1293 cpuid(7, &eax, &ebx, &ecx, &edx);
1295 /* if SGX is present */
1296 if (ebx & (1 << 2)) {
1298 rdmsrl(MSR_IA32_FEATURE_CONTROL, msr);
1300 /* if SGX is enabled */
1301 if (msr & (1 << 18))
1302 return;
1305 skl_cstates[5].disabled = 1; /* C8-SKL */
1306 skl_cstates[6].disabled = 1; /* C9-SKL */
1309 * intel_idle_state_table_update()
1311 * Update the default state_table for this CPU-id
1314 static void intel_idle_state_table_update(void)
1316 switch (boot_cpu_data.x86_model) {
1318 case INTEL_FAM6_IVYBRIDGE_X:
1319 ivt_idle_state_table_update();
1320 break;
1321 case INTEL_FAM6_ATOM_GOLDMONT:
1322 case INTEL_FAM6_ATOM_GOLDMONT_PLUS:
1323 bxt_idle_state_table_update();
1324 break;
1325 case INTEL_FAM6_SKYLAKE_DESKTOP:
1326 sklh_idle_state_table_update();
1327 break;
1332 * intel_idle_cpuidle_driver_init()
1333 * allocate, initialize cpuidle_states
1335 static void __init intel_idle_cpuidle_driver_init(void)
1337 int cstate;
1338 struct cpuidle_driver *drv = &intel_idle_driver;
1340 intel_idle_state_table_update();
1342 cpuidle_poll_state_init(drv);
1343 drv->state_count = 1;
1345 for (cstate = 0; cstate < CPUIDLE_STATE_MAX; ++cstate) {
1346 int num_substates, mwait_hint, mwait_cstate;
1348 if ((cpuidle_state_table[cstate].enter == NULL) &&
1349 (cpuidle_state_table[cstate].enter_s2idle == NULL))
1350 break;
1352 if (cstate + 1 > max_cstate) {
1353 pr_info("max_cstate %d reached\n", max_cstate);
1354 break;
1357 mwait_hint = flg2MWAIT(cpuidle_state_table[cstate].flags);
1358 mwait_cstate = MWAIT_HINT2CSTATE(mwait_hint);
1360 /* number of sub-states for this state in CPUID.MWAIT */
1361 num_substates = (mwait_substates >> ((mwait_cstate + 1) * 4))
1362 & MWAIT_SUBSTATE_MASK;
1364 /* if NO sub-states for this state in CPUID, skip it */
1365 if (num_substates == 0)
1366 continue;
1368 /* if state marked as disabled, skip it */
1369 if (cpuidle_state_table[cstate].disabled != 0) {
1370 pr_debug("state %s is disabled\n",
1371 cpuidle_state_table[cstate].name);
1372 continue;
1376 if (((mwait_cstate + 1) > 2) &&
1377 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
1378 mark_tsc_unstable("TSC halts in idle"
1379 " states deeper than C2");
1381 drv->states[drv->state_count] = /* structure copy */
1382 cpuidle_state_table[cstate];
1384 drv->state_count += 1;
1387 if (icpu->byt_auto_demotion_disable_flag) {
1388 wrmsrl(MSR_CC6_DEMOTION_POLICY_CONFIG, 0);
1389 wrmsrl(MSR_MC6_DEMOTION_POLICY_CONFIG, 0);
1395 * intel_idle_cpu_init()
1396 * allocate, initialize, register cpuidle_devices
1397 * @cpu: cpu/core to initialize
1399 static int intel_idle_cpu_init(unsigned int cpu)
1401 struct cpuidle_device *dev;
1403 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1404 dev->cpu = cpu;
1406 if (cpuidle_register_device(dev)) {
1407 pr_debug("cpuidle_register_device %d failed!\n", cpu);
1408 return -EIO;
1411 if (icpu->auto_demotion_disable_flags)
1412 auto_demotion_disable();
1414 if (icpu->disable_promotion_to_c1e)
1415 c1e_promotion_disable();
1417 return 0;
1420 static int intel_idle_cpu_online(unsigned int cpu)
1422 struct cpuidle_device *dev;
1424 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
1425 __setup_broadcast_timer(true);
1428 * Some systems can hotplug a cpu at runtime after
1429 * the kernel has booted, we have to initialize the
1430 * driver in this case
1432 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
1433 if (!dev->registered)
1434 return intel_idle_cpu_init(cpu);
1436 return 0;
1439 static int __init intel_idle_init(void)
1441 int retval;
1443 /* Do not load intel_idle at all for now if idle= is passed */
1444 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
1445 return -ENODEV;
1447 retval = intel_idle_probe();
1448 if (retval)
1449 return retval;
1451 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
1452 if (intel_idle_cpuidle_devices == NULL)
1453 return -ENOMEM;
1455 intel_idle_cpuidle_driver_init();
1456 retval = cpuidle_register_driver(&intel_idle_driver);
1457 if (retval) {
1458 struct cpuidle_driver *drv = cpuidle_get_driver();
1459 printk(KERN_DEBUG pr_fmt("intel_idle yielding to %s\n"),
1460 drv ? drv->name : "none");
1461 goto init_driver_fail;
1464 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
1465 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
1467 retval = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "idle/intel:online",
1468 intel_idle_cpu_online, NULL);
1469 if (retval < 0)
1470 goto hp_setup_fail;
1472 pr_debug("lapic_timer_reliable_states 0x%x\n",
1473 lapic_timer_reliable_states);
1475 return 0;
1477 hp_setup_fail:
1478 intel_idle_cpuidle_devices_uninit();
1479 cpuidle_unregister_driver(&intel_idle_driver);
1480 init_driver_fail:
1481 free_percpu(intel_idle_cpuidle_devices);
1482 return retval;
1485 device_initcall(intel_idle_init);
1488 * We are not really modular, but we used to support that. Meaning we also
1489 * support "intel_idle.max_cstate=..." at boot and also a read-only export of
1490 * it at /sys/module/intel_idle/parameters/max_cstate -- so using module_param
1491 * is the easiest way (currently) to continue doing that.
1493 module_param(max_cstate, int, 0444);